This invention relates to drive-transmitting means for transmitting drive selectively between a driving and a driven element. The driving element may be a cam or a crank and the driven element may be a reciprocating element.
The invention has been devised primarily for use in a reciprocating piston internal combustion engine to transmit drive selectively between a cam shaft and inlet and exhaust valves associated with the combustion chambers of the engine. During normal operation, each valve is required to execute a reciprocating motion which corresponds to the profile of an associated cam.